Socket contact for electrical connectors



March 31, 1970 F. T. ANDERSON SOCKET CONTACT FOR ELECTRICAL CONNECTORSFiled Jan. 31, 1968 ATTORNEYS.

United States Patent 3,504,331 SOCKET CONTACT FOR ELECTRICAL CONNECTORSFranklin T. Anderson, Bernardsville, N.J., assignor to Co-OperativeIndustries Inc., Chester, N.J., a corporation of New Jersey Filed Jan.31, 1968, Ser. No. 702,022 Int. Cl. H01r 11/22 US. Cl. 339-256 4 ClaimsABSTRACT OF THE DISCLOSURE A socket contact has two C-shaped metalspring members which embrace on opposite sides a cylindrical body memberwithin a circumferential channel. Radially, inwardly directed ends ofthe spring members engage in diametrically opposed longitudinal slots inthe body memher. The longer ends of the two springs project from thesame slot into the axial bore and function to frictionally engage amating pin.

The present invention relates to electrical connectors and, moreparticularly, to the socket contact for such connectors.

An electrical connector may take the form of either a receptacle or aplug. The purpose of either, when properly mated with the other, is toestablish a good electrical connection. Yet, by its very nature, theconnector is intended to provide for separation of the electricalconductors which the connector components serve to interconnect. Forsatisfactory operation, it is essential that the plug and receptacleboth stand up in the face of repeated assembly and disassembly.Moreover, the connector components must resist inadvertent disassemblyand must continue to develop good electrical contact when assembled.

Electrical contact between the plug and receptacle is generallydeveloped by bringing together a pin contact and a socket contact. As towhich connector component, the plug or receptacle, contains the socketcontact and which the pin depends on the particular installation. It isthe construction of the socket contact which constitutes the subject ofthe present invention.

In essence, the present invention is directed to the type of socketcontact which employs a rigid body member having a bore for receivingand guiding a pin when interfitted therewith, in combination with springmeans for frictionally engaging the pin and insuring good electricalcontact while developing adequate contact engaging and separatingforces. Prior constructions of this type have met with variousobjections. Often, the spring elements were easily dislodged from thebody member. In other cases, the spring elements were unduly deformedduring assembly with the body member thereby adversely affecting theiroperating capability. it has been difficult with prior constructions toestablish a satisfactory compromise to improve the spring retentionfactor while avoiding undue distortion during assembly. The problem hasbeen further complicated by the necessity for the sockets to remainoperable over an extremely wide range of ambient temperatures.

It is an object of the present invention to provide a socketconstruction which overcomes the disadvantages inherent in priorconstructions. A redundancy feature has been incorporated in the newsocket providing for increased reliability. The nature of the design issuch that the spring is subjected to no greater deformation duringassembly than is imparted to it during use.

In accordance with the present invention, there is provided a socketcontact for an electrical connector comprising a cylindrical body memberhaving an axial ice bore extending inwardly from a pin engaging end forreceiving a pin contact therein, a pair of diametrically opposedlongitudinal slots in the wall of the body member each providing radialcommunication between the bore and the exterior of the body member, anda pair of arcuate spring members embracing the body member, one on eachside thereof, the spring members having a radially inwardly directed endengaged in each of the slots with the member extending circumferentiallytherebetween, one end of each spring member projecting completelythrough its associated slot and for a distance into the bore forfrictional engagement with a pin contact upon insertion thereof into thesocket.

' The invention will be better understood after reading the followingdetailed description of a presently preferred embodiment thereof withreference to the accompanying drawings in which:

FIGURE 1 is an elevational view of a socket contact constructed inaccordance with the present invention with a pin about to be inserted;

. FIGURE 2 is a top view of the socket contact of FIG- URE 1;

FIGURE .3 is an enlarged sectional view taken along line 3-3 in FIGURE1;

FIGURE 4 is a longitudinal sectional view taken along line 4-4 in FIGURE3, but to the same scale as FIG- URES 1 and 2;

FIGURE 5 is a view similar to FIGURE 3 but showing the relationship ofthe socket parts with a pin inserted;

FIGURE 6 is a perspective view of one of the spring members employed inthe embodiment shown in FIG- URES 1 to 5; and

FIGURE 7 is a view similar to FIGURE 3 showing one of the spring membersin the process of being assembled with the body member.

The same reference numerals are used throughout the figures of thedrawings to designate the same or similar parts.

Referring now to the drawings, it will be seen that the socket consistsof a cylindrical body member 10 having an axial bore 11 extendinginwardly from the pin engaging end 12 for receiving a pin contacttherein, such as the contact 13 seen fragmentarily in FIGURE 1. A pairof diametrically opposed longitudinal slots 14 and 15 are formed in thewall of the body member 10'. Each of the slots 14 and 15 provides radialcommunication between the bore 11 and the exterior of the body member.

A pair of identical arcuate spring members 16 and 17 embrace the bodymember 10, one on each side thereof, within a circumferential channel 18axially spaced from the pin engaging end 12. The spring members 16 and17 each have radially inwardly directed ends 19, 20 and 21, 22,respectively, which are engaged in the respective slots 14 and 15 withthe spring member extending circumferentially therebetween. One end ofeach spring member (as best seen in FIGURE 3, the end 19 of spring 16and the end 21 of spring 17) projects completely through its associatedslot 14 and for a distance into the bore 11. The opposite ends 20 and 22of the spring members 16 and 17, respectively, have a length which issufficient to provide substantial retention of the spring membersagainst radial separation from the body member 10 but insufficient topass completely through the associated slot 15 into the bore 11.

FIGURE 3 shows the relationship of the spring members 16 and 17 relativeto the body member 10 prior to insertion of a pin. When a pin, e.g., thepin 13, is inserted in the socket it will assume the general positionshown in FIGURE 5 projecting or displacing the ends 19 and 21 of thespring elements radially outwardly while being urged by thevery samespring elements into intimate contact with the opposite side of the Wallof the bore 11 where the slot 15 is located. As seen in FIGURE 5, thedepth of channel 18 is such that no part of the spring member 16 or 17projects radially beyond the external surface of the body memberadjacent the channel.

Both the ends 19 and 21 of the two spring members bear firmly againstthe pin 13 at spaced apart points 23 and 24. These points 23 and 24represent line contacts since, as best seen in FIGURE 6, theintermediate portion 25 of the longitudinal edge of ends 19 and 21 isstraight and parallel to the longitudinal axis of the C- shaped memberwhich has been formed from spring sheet metal.

Still referring to FIGURE 6, it will be seen that on opposite sides ofthe intermediate portion 25, the edge is tapered at 26 and 27. Thetapered portions 26 and 27, depending upon the orientation of the springmember relative to the body member 10, cooperate with the rounded nose28 of the pin 13 (best seen in FIGURE 1) for proper camming action asthe pin is inserted into the socket.

While the details form no part of the present invention,

it will .be observed that the socket is provided wi.h a solder cup 29 atthe end opposite its pin engaging end. This is best seen in FIGURE 4.

Referring to FIGURE 3, notice should be taken of the two radiidesignated 30 and 31 radiating from respective origins 32 and 33 whichare separated a distance 34. While these do not represent criticaldimensions, they do represent dimentions which it has been founds canreadily be controlled to provide optimum results. As shown, the twocenters 32 and 33 are displaced, along a line normal to the line passingthrough the centers of slots 14 and 15, a distance equal to thethickness of the stock used for spring member 17. This discussion, forconvenience, is limited to spring member 17, it being understood thatmirror symmetry exists around the line 44 and that element 16 isidentical to element 17 but reversed in orientation.

Prior to assembly with the body member 10, the radius 31 of the insidesurface 35 of spring member 17 is chosen slightly smaller than theradius 30 of the outside surface of the body member in the channel 18.The difference in radii should be chosen such that when the spring isassembled with the body member as seen in FIGURE 3 there is slightfrictional engagement between the spring member 17 and the body memberimmediately adjacent the slots 14 and in the vicinity of the points 36and 37. At most, it is preferred that there be no play at these points.As an example, with a radius 30 of .044 inch, the radius 31 was chosenbetween .042 and .043 inch. With a bore of approximately .067 inch indiameter, the ends 19 and 21 of the spring members were arranged toproject approximately .01 inch therein,

As seen in FIGURE 7, the spring member 17 (and in similar manner themember 16 which is not shown) can be assembled with the body member 11without unduly deforming the spring member. This is accomplished byfirst inserting the longer end 21 into its slot 14 and then urging theshorter end 22 into the opposite slot 15, as shown. It has been foundthat by proportioning the parts as shown in the drawings the assemblycan be made without excessive distortion of the spring and with thesliort end 22 or achieving significant anchorage in the slot 15. Infact, the amount of displacement or deformation of the spring elementnecessary to assemble the spring with the body member as seen in FIGURE7 is approximately the same as the displacement developed by insertionof a pin within the socket as seen in FIGURE 5.

An inherent advantage, not previously mentioned but evident from anexamination of FIGURE 5, derives from the side-by-side disposition ofthe two ends 19 and 4 21 of the two springs-in the single slot-14. Itwill be seen from FIGURE 5 that the spring ends 19 and 21 tend toprovide mutual support for each other to prevent buckling or unwanteddeformation upon insertion of pin 13. Numerous other advantages willoccur to those skilled in the present art.

Having described the presently preferred embodiment of the invention, itshould be understood that numerous changes may be made therein withoutdeparting from the true spirit of the invention.

What is claimed is:

1. A socket contact for an electrical connector comprising a cylindricalbody member having an axial bore extending inwardly from a pin engagingend for receiving a pin contact therein, a pair of diametrically opposedlongitudinal slots in the wall of said body member each providing radialcommunication between said bore and the exterior of said body member,and a pair of generally C- shaped spring sheet metal members having anend engaged in each of said slots, the ends of the spring membersengaged in one of said slots both projecting completely through said oneslot and for a distance into said bore for frictional engagement with apin contact upon insertion thereof into said socket, the lengths of theopposite ends of said spring members being sufficient to providesubstantial retention of said spring members against radial separationfrom said body member but insufficient to pass through the associatedslot into said bore, the dimensionat least some clearance exists betweenthe spring members and the body member around the body member betweensaid slots.

2. A socket contact according to claim 1, wherein said spring membersare disposed in a circumferential channel in said body member axiallyspaced from the pin engaging end thereof, the depth of said channelbeing related to the dimensions of said spring members and the assembledclearance therebetween such that said spring members at no time projectradially beyond the external surface of said body member adjacent saidchannel during normal use of said socket, and said slots are confined tothe Width of said channel.

3. A socket according to claim 1, wherein the ends of the spring memberswhich project completely through said one slot are each formed with alongitudinal edge having an intermediate portion parallel to thelongitudinal axis of the corresponding spring member and having endportions which are both tapered.

4. A socket contact according to claim 1, wherein the C-shaped springmembers intermediate their ends, at least prior to assembly with saidbody member, are cylindrical in form with a radius of curvature slightlyless than that of the surface of the body member which it embraces.

References Cited UNITED STATES PATENTS MARVIN A. CHAMPION, PrimaryExaminer JOSEPH H. MCGLYNN, Assistant Examiner US. Cl. X.R. 3 39262

